The prior art has used many methods of stopping the wild gushing of oil or gas from well casings. The way used in Kuwait after the war with Iraq is to pump large volumes of mud or cement down the well casing to make it quit flowing.
This method then requires expensive removal of the mud or concrete, such as by drilling.
Not only is this expensive, but is consumes much time. Hundreds of oil well casings have been broken off in Kuwait, many of them below ground where the top of the casing is covered by a pool of oil and cannot be seen.
The plugging system hereof provides the concept of an inflatable plug on a tube, the tube being inserted in the well and then the plug is expanded with a fluid such as water or a gas to stop the flow. The prior art has many concepts involving the use of inflatable plugs. But in all cases there are major differences in principle and structure from the system hereof.
Oil pressure is very great and the concept of a restrainer of stiff material is provided to hold the flexible plug in place against great pressure.
Remote control of release of pressure into the tube and from the tube are concepts provided herein.
For plugging oil wells on massive scale, it is important that an expensive crane not be tied up in working at a single well location except for a very short time. For that reason a two-clamp tube holder concept is provided herein, holding the inserted tube to the oil well casing so that the crane is freed to be moved to a different well until needed for the tube and plug removal.
When an oil well casing has been broken off deep in the ground, such as by a vandalism explosion, the system hereof is excellent. The plugging can be done by passing the plug tube down through the oil puddle above the casing, though the casing cannot be seen as this makes great difficulty. However to assist emplacement of the plug-tube into an underground well casing, a first step can be to lower a special funnel toward the casing. This can be done by attaching the funnel around the plug-tube. The wide downward end of the funnel is easier to guide onto the casing than the narrower plug-tube. As the funnel has a long support frame extending upward, the funnel frame can be put around the plug tube and then both are lowered together until the funnel engages the casing. The funnel then guides the plug into the casing.
The special funnel is then removed horizontally from the plug-tube by first opening hinging sections of the funnel and its frame. The funnel is then lifted out of the way.
After the flow has been stopped with the system hereof by the use of a gate stop valve, then a globe valve, not shown, can be put above, and attached to, the gate stop valve.
A globe valve is better for day-to-day flow regulation than a stop valve.